/// @description 定时添加
// You can write your code in this editor

//添加残影
for(var i=shadow_num-1; i>0; i--)
{
	shadow_arr[i, 0] = shadow_arr[i-1, 0];
	shadow_arr[i, 1] = shadow_arr[i-1, 1];
}
shadow_arr[0, 0] = x;
shadow_arr[0, 1] = y;

//重启定时器
alarm[0] = shadow_tim;
